1. Field of the Invention
The present invention relates to a mobile communication system. More particularly, the present invention relates to a mobile terminal and system scan method thereof that is capable of effectively acquiring system information.
2. Description of the Related Art
In a cellular mobile communication system, a mobile terminal selects a base station by which it is served and receives system information from the selected base station. The mobile terminal provides the base station with its location and registration information using the system information such that the base station can serve the mobile terminal. When the system information is acquired, the mobile terminal registers the acquired system information (hereinafter referred to as “channel”) to a Most Recently Used (MRU) list.
Here, the term “system” denotes a mobile communication system, provided by a specific mobile operator, including analog and digital cellular system and Personal Communication Service (PCS) system.
In the meantime, when a mobile terminal loses connection with the system, it performs system scan according to preset system scan conditions. According to the system scan conditions, the mobile terminal operates in a scan mode or a power saving process. The scan mode and power saving process are alternating. In order to acquire the system information, the mobile terminal scans the systems registered to the MRU list in priority order and then scans channels listed in a Preferred Roaming List (PRL) provided by the mobile operator in priority order of preference.
In a case that a number of the channels listed in the PRL, the operation mode of the mobile terminal is likely to be transitioned to the power saving process before the mobile terminal completes scanning all the channels in the scan mode, thereby elongating the time it takes to acquire the system information. Also, the conventional system scan method has a drawback in that it takes a long time to acquire the system information especially in a weak electrical field below −100 dB since most of the channels listed in the PRL are scanned in a micro-scan mode, whereas a small number of channels are scanned in a full-scan mode.
Therefore, a need exists for an improved system scan method and a terminal having the same, which is capable of effectively acquiring system information.